QmlDesigner: Do not escape "\" for unicode chars

Task-number: QTCREATORBUG-12616
Change-Id: If8cac8d35cb97f59e12d1609f808dd639f93f315
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/qmldesigner/designercore/model/qmltextgenerator.cpp

@@ -273,6 +273,9 @@ QString QmlTextGenerator::escape(const QString &value)
 {
     QString result = value;
 
+    if (value.count() == 6 && value.startsWith("\\u")) //Do not dobule escape unicode chars
+        return result;
+
     result.replace(QStringLiteral("\\"), QStringLiteral("\\\\"));
 
     result.replace(QStringLiteral("\""), QStringLiteral("\\\""));

tests/auto/qml/qmldesigner/coretests/tst_testcore.cpp

@@ -993,6 +993,37 @@ void tst_TestCore::testRewriterChangeImports()
     QCOMPARE(model->imports().first(), Import::createLibraryImport("QtQuick", "1.1"));
 }
 
+void tst_TestCore::testRewriterUnicodeChars()
+{
+    const QLatin1String qmlString("\n"
+                                  "import QtQuick 2.1\n"
+                                  "\n"
+                                  "Text {\n"
+                                  "    text: \"test\""
+                                  "}\n");
+
+    QPlainTextEdit textEdit;
+    textEdit.setPlainText(qmlString);
+    NotIndentingTextEditModifier modifier(&textEdit);
+
+    QScopedPointer<Model> model(Model::create("QtQuick.Rectangle"));
+
+    QScopedPointer<TestRewriterView> testRewriterView(new TestRewriterView(0, RewriterView::Amend));
+    testRewriterView->setTextModifier(&modifier);
+    model->attachView(testRewriterView.data());
+
+    QVERIFY(testRewriterView->errors().isEmpty());
+
+    ModelNode rootModelNode = testRewriterView->rootModelNode();
+    QVERIFY(rootModelNode.isValid());
+
+    rootModelNode.variantProperty("text").setValue("\\u2795");
+
+    const QLatin1String unicodeChar("\nimport QtQuick 2.1\n\nText {\n    text: \"\\u2795\"}\n");
+
+     QCOMPARE(textEdit.toPlainText(), unicodeChar);
+}
+
 void tst_TestCore::testRewriterForGradientMagic()
 {
     const QLatin1String qmlString("\n"

tests/auto/qml/qmldesigner/coretests/tst_testcore.h

@@ -139,6 +139,7 @@ private slots:
     void testRewriterActionCompression();
     void testRewriterImports();
     void testRewriterChangeImports();
+    void testRewriterUnicodeChars();
 
     //
     // unit tests QmlModelNodeFacade/QmlModelState